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CB550K Points Plate Issue [SOLVED]

Maraakate

Veteran Member
Joined
Jun 7, 2022
Total Posts
2,418
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566
Location
Lancaster, PA, USA
Hey everyone,

I've been having some problems this season with the 550 holding a good idle. When the bike is cold, runs and idles quite well, but after about 5-10 minutes when it's warmed the spark starts cutting out at idle it appears and then I have to keep blipping the throttle here and there. When actually moving it drives great.

I've cleaned the carbs multiple times years ago, new OEM float needles and OEM gaskets/o-rings, including intake. So with all that said, I decided to do a compression test and all 4 cylinders are within 5 psi of each other (did this while mildly cold, bike sat after a 10 minute ride for a couple of hours). Didn't take exact readings but they were about 150-155psi. So the engine is in pretty decent shape and valves are probably adjusted OK. I adjusted the valves last season before putting the bike in storage.

When I took the plugs off, 3 of the 4 were whitish with deposits, indicating a lean condition. The fourth plug was a bit sooty. One of the plugs the gap was a bit wider than the others so I fixed the gap on it. Wasn't extreme, but enough to notice.

I grabbed a large truck battery that was fully charged, hooked it up to the bike, started it up with a timing light and just watched as it idled. What I found is that the ignition is too advanced (I forget the marks will attach a picture below, I always get this part confused as I don't do it enough) I believe. It's not at the 'F' marks for the appropriate cylinders. It's quite a bit more forward. If I recall, two years ago it was a bit off the 'F' mark but not extreme and now I remember that I couldn't get those screws out in order to rotate the plate to change it. 2-3 seems to bounce a bit between two points which could indicate a problem with that particular coil or possibly points or condenser. And yes, changed the inductive clamp on one side of the plug cap vs the other to make sure. It's the same in either direction.

At this point I've tried:

  • One of those Vessel brand screwdrivers that claims to be JIS (not quite JIS I've noticed, but pretty close usually works 90% of the time get the screws out)
  • The actual JIS screw that came in the tool bag
  • Taking the tool bag screwdriver and putting a pair of pliers on the handle
  • Taking a mini sledge to the handle of the Vessel screwdriver as I turn it either direction.
  • Spraying penetrating fluid in each of these 3 screws multiple times (making sure to put a rag over the points)
  • Using a butane torch over the screws (this approach didn't work as well, doesn't seem to get hot enough)

I'm thinking I may need to get a real JIS bit for my impact. Usually my impact will get the stuff out, but this was starting to round it slightly and I stopped using it. The screws are still in good shape and the JIS tools fit in it so I don't want to muck that up. Anyone have advice on this? I'm guessing they have never been adjusted before and if it's too advanced then maybe that's why the plugs were whitish with some white buildup on the plug and maybe it's why my idle starts cutting out once the bike is warmed up. My plan is to just keep coming back every now and again and spraying penetration fluid on it and maybe it will eventually come out. It's pretty clean in there, so I think it's just all the heat/cool cycles over 40+ years.

I've attached a picture of the marks from the book. It's quite a bit off, I've marked where I think it generally is in red. Can someone confirm that means I'm too advanced? I always forget the rotation and how that works.

Untitled-1.jpg

NB: Please don't tell me to take this thread to SOHC4. Not a big fan of that place for various reasons I won't get into here.
 
OK. After much goofing around I finally got it off and readjusted the timing. I had to use the penetrating fluid multiple times, then the mini sledge on the screwdriver and coupled with the butane torch again. Got the timing set where it needs to be.

Let it idle for 5 minutes while I was cleaning up and for once the idle wasn't hanging which was nice. Took it for a good 10-15 minute ride pretty hard, ran great, came back. Shut the bike off, and started it right back up and now I have the same bologna. The bike just doesn't want to idle after it's warmed up. I tried things like shutting the gas off, and playing with the choke (choke works properly, including the fast idle).

The only other thing I can think of that is possible related -- Last year I was driving home from work and bike was incredibly loud all the sudden. I couldn't figure it out, took me days to narrow it down to being an exhaust gasket leak apparently. I say apparently, because I tightened up the nuts on the studs as a last resort of listening around with a stethoscope and the noise went away like 3 seconds later and never came back. Then the bike started getting some grey smoke out of the exhaust after it got warmed up around the same time. At idle, after a few seconds of being at a stop light. It looks like it's a bit worse now. Since compression is good, I wonder if it's valve seals or something silly. And if so, would it really make this bike that much of a bear to hold an idle?

One thing I noticed as I was here fooling around with trying to get the idle right was that I could see some purple sparks come off the cap on cylinder 4. Never could see it before, but the garage wasn't lit very well so it was obvious this time. I got excited, thinking that was it. I grabbed a cap of a parts coil of the same make/model put it on and didn't change anything. Other ideas is that the condenser/points/coil is weak or bad and at idle it just doesn't work well when it's hot. But, from what I can tell, normally that means the bike doesn't run at all, and after it cools down for 10 minutes it will start again and stop running again pretty quickly. I just went through this with my DT250 last year, put a new coil on that and it runs fine.

I will say, when the idle no longer holds then it's a real pain of cranking to get it to start again. It will start but I gotta play around with the throttle position while I do it. It just doesn't make sense to me that if the carb had an issue, that it would only happen when it got warm with the idle circuit. You would think the rest of it wouldn't run right when cold.

I'm pretty much out of ideas at this point. Carbs may be part of it, but I don't think that's all of it.
 
Those external "purple sparks" mean that coil output ground is happening before ignition spark gets to the plug (not firing inside cylinder).......

Please phone to discuss remedy.......
 
Gave 66sprint a call. He suggested to just pull them carbs and take a look. Always hate doing it on this bike, but looks like I have no choice. Specifically, checking the plug passages (if it has them on this carb, i don't remember) and idle jets. I'll do that, and other suggestion is checking connectors on the coil, points, and condensers and ohming out the caps and coil. Other suspicion may be the condensers themselves. And rechecking carb sync and idle mixture. Admittedly, haven't checked that for a couple of years, but maybe it needs revisited.

I'll give all of it a try over the next few days and report back. Hoping he's right and that it's just something stupid. It usually is, and I'm probably overthinking whatever it is. :lol:
 
Hey Tom,

Can you rename this thread to 77 CB550K Idle Issues After Warmup? I solved the screw issue on the points plate, but thread still on-going while I try to narrow down the rest of it.
 
GF is sick, so I have to help her and the 3 children. This bike doesn't fit in my garage (I only have a regular door, it was a car-port someone converted into a garage) so I have to work on this in the trailer at night. With that said, I did do a charging test, as I do remember these bikes are picky about battery voltage. It charges up to 13.5V or so when you whack the throttle and hold it around 5K or so. After that, I took it for a real ride, like 30 miles all over the place. Rode it like I stole it. Normally, I shift kind of early around 4K-5K. But was staying mostly around 6K cruising and would shift around 7K. Had no problems at all. Even pulled over at one point to answer a text, left it idling while I did so. Came to many stops as well and just hung out at the light for a good 20 seconds. I readjusted the idle after about 10 miles. Didn't need much, just a slight bump down.

I got back, pulled the bike in and let it idle while I looked in the dark to see if there was any more caps grounding out. Didn't see any. Shut the bike off, immediately restarted it. It was good. Let it idle for about 10 seconds. Shut it off again, this time tried the kickstart. Couldn't get it after 3 kicks. Hit the starter, had to crank it for about 5 seconds. It started but had to keep giving it throttle. Back to that same idle issue. One of the cylinders definitely wasn't firing at that point. So, while I was holding it around 2K, went back out for a ride. Gave it some hell going out of the driveway, then the cylinder was firing again and it was idling just fine. Rode it around for another 10 miles just as hard as before and all is good. Let it idle in the trailer for another 30 seconds before I shut it off, again checking the caps.

I know 66Sprint said about getting the carbs off, but I'm working in the dark right now due to the GF being sick and of course the battery was dead in the headlamp :lol:. With that said, I think what really needs to happen here is I need to do a true tune-up. I did the valves last year before I put it away. But I think I need to trim the coil wire back slightly, put all new caps on it, clean the points well (they don't have pitting but theres some whitish marks on them, not sure if this is alarming or not?), check the points GAP (I only fixed the timing marks, so the gap may be off), new plugs, float height, idle air mixture, and carb sync.

My theory is as soon as the bike shuts off some component is slightly overheating now that's it not pushing some air and it makes it hard to restart. If that's the case, I'm not really sure how you could test the coil output while running, except maybe with a high voltage probe (which I actually do have) and trying to ride it around and see if it starts increasing exponentially in resistance after it gets good and hot and when parked. Other theory is the slippers or where the ride on are worn and get funny when very hot or even the condensers. I do think that plug cap on cylinder 4 that was grounding was part of an issue, and that the advance was too far forward and probably why 3 of the plugs were white.
 
Sorry to hear the GF is sick, hopefully it's not Covid and she gets well soon.

At this point I'd replace the condensers just for good measure, along with the plug caps absolutely (and trim the wires too as you mentioned). Points gap does matter, of course (contrary to Common Motor's beliefs) so once the new parts are in, set the points and timing and see how it does. After that all you'd have left to wonder about would be the coils, though if it runs well under heavier load like 7000 rpm or above then they're probably okay.
 
Its not covid she tested herself multiple times this week. Just a really annoying head cold. She pushes herself very hard so I think it just finally caught up with her and her body is forcing her to rest.

I ordered new caps from DSS. Ordered a denso plug from AZ because you can't get D7ES any more. Apparently the denso plugs last longer too.

Yeah, I think the coil is probably OK. When I've seen them go bad they just simply give it up after a short time of riding and will not spark at all until they cool down. Then you fire it up and they shut off again almost immediately.

I'll take a picture of the points later to get an opinion from you guys. I think its just normal wear, but unsure. DSS has OEM replacement points but unknown if they are TEC. I've been told before you want to avoid Daichi and use the same brand of points on your points plate or things dont work right. Is this true?

EDIT: In interest of archiving/searching. The plug that's been recommended as a replacement to D7ES is Denso 4099/X24ES -- https://www.amazon.com/gp/product/B000HCRNZQ/

Plug caps for 1/4 are NGK XD05F and 2/3 are NGK VD05F.
 
Points gap does matter, of course (contrary to Common Motor's beliefs)

And yes, I should have checked the gap before hand. Just forgot to do it. I did check them sometime last year. But considering how much the advance changed in the past year, it's quite possible the gap has changed as well. Interesting, because I am pretty silly about popping that cover off and keeping the felt and shaft lubed. It was recommended to me years ago to just use Standard SL-2 Lubricam -- https://www.ebay.com/itm/165527568738. Not the cheapest price at that link, but can't find it on AZ any more. Just look around. I always put some on the cam and put a couple of drops of SAE20/3-in-1 on the felt if it's dry and put a dab of the SL-2 on the felt.
 
Ordered the aftermarket condensers from DSS just now as well. Forgot that I should have ordered 3 new replacement screws for the points plate anyways, PN: 93891-05012-00. I got mine off after much work, as stated earlier in the thread, and are reusable but don't trust them any more and they're cheap so why not?

Will report back in about a week or so on how everything worked out. Also looked at the book last night and it should be 14.5V at 5K. No worries, it just means I probably need to move the adjustment screw in the regulator just a touch to get it there. I took it apart last year and readjusted the gap and such and cleaned the contacts on it. But, that was "tuned" to a battery that was on it's last season. So, I'll get that squared away too just so we can cross that off the list of any other potential gotchas.
 
Good to know it's not Covid.

I've been told before you want to avoid Daichi and use the same brand of points on your points plate or things dont work right. Is this true?

I know the Daiichi points for some of the twins, possibly all, are not the best but I don't recall if they're also a problem for the 4 cylinders, been waaay too long since I've even adjusted 4 cylinder points (my last CB750 was early 1980) but it is true that the points and plate brad work best together, possibly not work at all if different. Again, disconnected from it too long since all my multi-cylinder bikes after that had factory EI.

The plug that's been recommended as a replacement to D7ES is Denso 4099/X24ES

Interesting, because in ND the 24 typically equates to the 8 in NGK (W24ES = B8ES) so they would seem to be the colder 8 heat range, not 7
 
And yes, I should have checked the gap before hand. Just forgot to do it. I did check them sometime last year. But considering how much the advance changed in the past year, it's quite possible the gap has changed as well. Interesting, because I am pretty silly about popping that cover off and keeping the felt and shaft lubed. It was recommended to me years ago to just use Standard SL-2 Lubricam -- https://www.ebay.com/itm/165527568738. Not the cheapest price at that link, but can't find it on AZ any more. Just look around. I always put some on the cam and put a couple of drops of SAE20/3-in-1 on the felt if it's dry and put a dab of the SL-2 on the felt.

I've always used PJ-1 chain lube on the points breaker blocks and felt, with the graphite in it and the thickness it congeals to it lasts a really long time and doesn't spread around.
 
Good to know it's not Covid.



Interesting, because in ND the 24 typically equates to the 8 in NGK (W24ES = B8ES) so they would seem to be the colder 8 heat range, not 7

You're right. I see the book says X22ES to be used instead as B7ES replacement. I'm not sure if it will really make a difference with my riding. Guess we'll find out.
 
EDIT: Stupid question i answered myself by reading my owners manual. I kept meaning to say D7ES. I have D7EA and spare D7EAs currently. This is the direct replacement right? My Honda dealer and all online vendors think so.
 
Does the resistance of caps and plugs added up to what is acceptable for the coils ?

Unsure, will have to check the book values. Which I will do when I go to hook it all up over the next few days. I need new caps anyways, they are original.
 
Got the parts from DSS today. May or may not get time this evening to do it. If not, probably won't get around to it until Monday evening. Will be certain to ohm out the coils and report the results.

To recap this is what I've bought:

* XD05F caps for 1-4
* VD05F caps for 2-3
* Genuine NGK D7EA plugs purchased from the dealer
* Aftermarket condensers from DSS
* 3 new screws for the points plate since I had to really work at getting the old ones off

My plan (in order):

* Pull off old caps, trim the wire back a bit on each coil, ohm it out, write down the results.
* Put the new caps on.
* Put new plugs in.
* Replace the condensers and screws.
* Clean the points, and take pictures of their current state for this thread.
* Set the gap FIRST.
* Statically time the marks SECOND.
* Recheck.
* Start the bike, use my timing light hooked up to an external power source, such as my large car battery.
* Verify dynamic timing with the light, adjust as needed.
* Recheck gap a final time if it has changed from having to adjust after dynamic timing.
* Bump the voltage regulator from 13.5V to 14.5V (this is the book spec, seems I'm a bit low so need to adjust it a bit. I adjusted it last year including the gap, etc., but probably did set it for 13.5V instead of 14.5V by mistake)
* Ride it and see what happens.
* If problem still occurs, when I get back, take a reading of the coils with the multimeter and see if it has drifted substantially and report back.
 
Sounds like a good plan. Doesn't that large plate also have a small sub-plate for the right set of points? It's been a long time since I've seen a 4 cylinder with points and even longer since it was a 500 or 550.
 
Yes, the sub plate is for 2-3. Not too hard to get it all dialed in if you got a strobe light. Didn't get time to do it tonight, will probably be Monday when I get around to the fun.
 
I had some time this morning to do the caps, plugs and condensers. I found some interesting quirks upon further inspection.

First, the caps were all XD10F and they should be VD05F on 1-4 and XD05F on 2-3. The cap on cylinder 1 was an XD10F clone. No markings and I was unable to measure it out. So it seems it was faulty or intmittently faulty.

Measurements at tension wires for 1-4 were 14.7K ohms. Primary at yellow and b/w was 4.5 ohm.

Measurements at tension wires for 2-3 were 16.5K ohms. Primary at blue and b/w was also 4.5 ohms.

I put new bullet connectors on the coil wires. The yellow coming from harness had some green corrosion on it and the weather pvc sleeve was melted a bit so I figured I'd do them all. The twin bullet connector for b/w from harness side actually had dead bugs and mud in it. When I attempted to clean it it broke so I soldered a y to it with new bullets as I didn't have a twin bullet in my stock. I'll have to get a hold of Matt at some point to change it to the proper type.

I replaced the condensers as well and checked the gap. Gap was at 0.27mm not 0.30mm. Didnt have time to goof with that but I think this should be OK for now until I get more time this week?

Attached is pictures. Note the dirty plug from cylinder 1. That was the one with the aftermarket cap.

Plugs in order from 1 thru 4. They have since been replaced.
20220716_105904.jpg
20220716_105915.jpg
20220716_105924.jpg
20220716_105938.jpg

Dead bugs and mud in the twin bullet connector.
20220716_111256.jpg

New bullet connectors. The y for b/w was double heat shrinked and used wire harness tape over the heat shrink for good measure. Will replace with proper twin bullet connector at a later date.
20220716_105844.jpg
20220716_105837.jpg

I took the bike put for a 10 mile ride and it idles very well now. Came back, did a few quick restarts of the engine it was fine. Went inside for 10 minutes to take care of something. Started it again just fine and drove another 10 miles. So I think its OK now. The caps being wrong, and old was probably a big factor besides the timing being way too advanced. Will drive it more over the week and report back.
 
All the little stuff adds up, seems you found everything that was contributory. Good to hear it's running well again.
 
All the little stuff adds up, seems you found everything that was contributory. Good to hear it's running well again.

Thanks. I am a bit puzzled on the coil specs. I checked the FSM and Chilton they don't list specs in either except capacitance for the condenser and resistance just for the caps. Considering the primaries both read 4.5 ohm dead on I guess thats ok. There is a 2k delta between the tension wires. Does anyone know what the serviceable spec is for the OEM coils? I have a spare used set and ill ohm them out over the next few days to compare.
 
As long as the resistance of every coil is more or less the same, you're fine. However, if the plugs have a build-in resistor and the caps have a build in resistor, you have to be sure not to exceed the maximum resistance that the coils can handle.
 
Right, I'm using resistor caps and no resistor plugs and they were the direct parts listed in the fiche so should be OK.
 
I think we can mark this as [SOLVED]. I had about 30 minutes of "play time" today and ripped it around for a good 15 miles, including a stop at the gas station to fill up. Idles better than it ever has and fired right up after I filled up (something that has been a problem for quite some time). I got back. Let it idle on the center stand for 30 seconds. Shut it off, let it sit for a minute, kick started right up. Let it idle again for 30 seconds. Shut it off. Put some tools away, then I came back and it kick started it right up again.

I guess it was just that combo of bad caps, making the plugs get crappy and the timing being too advanced.

I still gotta readjust the voltage regulator from 13.5 to 14.5 but will do that some time this week when I get more time. Probably Friday.

P.S. I checked with DSS and the points plate and OEM points they have for this bike are TEC. So it's probably in my interest to purchase a set in the future.
 
Yes, before that supply starts to dwindle as well.

Glad it's sorted now, I'll mark the thread solved.
 
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